The Overview & Timeline
The Depletion of the Stratospheric Ozone Layer By Chlorofluorocarbons
The following is an overview of the entire case study. Each page is listed separately. If the page numbers are clicked, the appropriate page will be accessed. Important dates that appear on each page are also listed under each section. If any of the dates listed are clicked, the appropriate page will be accessed. By clicking the phrase, "Additional Dates of Interest," a page with more information about other dates pertaining to that page will appear. Finally, a brief synopsis of the material contained on that page is also included for each page designation. Clicking the word synopsis will access the text.
Spring 1851-- Dr. John Gorrieinvents the first working
refrigerator.
1871-- Mendeleev's periodic tables published in English.
Many empty spaces appear where soon-to-be discovered elements will be placed.
June 1918--General Motors begins manufacturing
refrigerators for purchase by the general public.
December 31, 1928-- The first patent is given for the
formula for chlorofluorocarbons (CFC).
April 1930-- Midgley makes a presentation
demonstrating the safety of CFCs.
August 27, 1930-- General Motors and DuPont enter
into a joint venture to produce and market CFCs.
1932-- The Carrier Corporation markets the first
self-contained household air-conditioning unit, "The Atmospheric
Cabinet."
September 8, 1941--Thomas Midgley Jr. receives the
American Chemical Society's Priestly award for outstanding creativity in the
field of chemistry.
1956-- America's first air-conditioned mall opens in
Edina, Minnesota.
December 1973-- Rowland and Molina theorize that CFCs
can destroy the ozone in the stratosphere.
December l974--The first government hearings are held on
the CFC-ozone theory in the United States.
August 1981--NASA scientist Donald Heath announces that
satellite records show global ozone levels have declined 1 percent.
September 1987--The Montreal Protocol is signed,
calling for eventual worldwide CFC reductions of 50 percent.
1990-1993-- DuPont's research and development arm produces
substitutes for CFCs. These include partially hydrogenated chlorofluorocarbons
(HCFC) and totally hydrogenated chlorofluorocarbons (HFC).
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